what is the difference between kill -9 pid and kill pid command ? Do they have different behavior ? i know that -9 is for "SIGKILL" signal

Is there a difference between   kill -9 212121   and  kill 212121


So the full problem was:      Consider $R=\mathbb Q[x,y,z]/(x-xyz)$. Prove that $x$ and $xy$ divide each other in $R$ but that they are not associates. In other words, there is no unit $u\in R$ so that $x=xyu$.    I already proved they divide each other but I need to prove no unit exists.

Please help me to find elements $a,b$ in a ring $R$ such that $a\mid b$ and $b\mid a$, but there does not exist any unit $u$ in $R$ such that $a=ub$.


As I have many pictures in which I have taken from my mobile phone whose picture quality comes good but not good as DSLRs or any HD quality camera.  To look my photo or the main object in picture look HD or attractive towards others and not feel them bad by the looking at the poor quality of photo.  So can any one help me out to solve my problem?

I know cell phone cameras are the lowest rung, but when reading reviews of phones, the reviewers always have sample shots that are much better than what I can manage.  What are some ways to take decent shots with a cell phone camera?  (I'm thinking of the higher end Android or iPhone cameras).


When I was applying for a Spouse visa in 2016, the questioning was a bit different: it clearly stated criminal offense. I answered I had no penalties and got the visa. Now the wording is: At any time have you ever had any of the following, in the UK or in another country?.. A caution, warning, reprimand or other penalties  Because it no longer mentions "criminal", I am not sure whether I need to disclose my penalties.  Please advice!  Some background information:  I have been driving in Russia for 10 years and got multiple speeding tickets (which I paid and never saved a copy of). I also believe I have been issued tickets for crossing the road in the wrong place as a pedestrian, having dirty car number plate etc.  I don't think any of it is considered a criminal offense in Russia, as only drunk driving, extreme speeding (up to 60km/h) etc leads to police revoking your driver's license for a period of time. Everything else is just a fine - we have no points-based system here.   All the speeding tickets were issued in my gran's name, as the car is registered on her Some of the small tickets (mentioned above) were issued in my name

I have been filling in the UK visitor visa application online, and there is a section under convictions and other penalties:     A. Penalty for driving offences, e. g., disqualification for speeding or no insurance   Last year, in Australia, I received fine for not stopping at a red light, caught on a traffic camera, and incurred 3 demerit points on my driving record.  Do I need to declare that under this section?  It never went to court. I received the notice of the fine by mail, and paid it in full.   I have checked with the Australian authorities who confirmed that I do not have a criminal record for this; it is only recorded on my driving licence.  Is it something that is expected to be declared on the visitor application form?  I wouldn't mind disclosing it, as it is a common traffic offence and a lot of people have the same on their licence. I am worried that it might be a reason to be refused a visa.


I am running Mac OS X and I have two different Internet connections on two different local networks: One is wireless and the other is wired. I want to use both on the same time to get higher download bandwidth. I saw Nvidia has something like that called “”  So can I download using my two networks in the same time if the download server allows it.

I understand that any one connection (such as a non-p2p download) will use just one of the connections, but since most normal activity involves multiple connections at once, I can still in theory increase my overall bandwidth by sending some traffic over each connection.  See also the following similar questions, most of which are for windows:            Here's my partial self-answer:  You can use ipfw to direct outgoing traffic. For instance, if you want udp (such as most bittorrent traffic) to use one connection while everything else uses the other, make sure the general-use connection is above in the network control panel, then type:  ipfw add fwd ip.for.bittorrent.router udp from any to any out   at the command line. (Or use WaterRoof, the ipfw gui; then you don't need the "ipfw add" part.) Note that that's the router ip (typically similar to your ip but ending in .1).


I have a windows ultimate 32 bit with 2 monitors, multiple displays set to: "Extend these displays" After hibernate, all the windows are back in the first monitor, and I need to re-drag them (or Win-shift-arrow them) all over again.  Any ideas?  it seems like a duplicate of:  but I didn't see a clear answer in there...

When I lock my Windows 7 Pro 64bit desktop and then unlock it after the screen saver has activated I find that all of the windows that were on monitor 2 (right side) have moved to the lower right of monitor 1 (left side).  Also all of the windows on monitor 1 have moved to the lower right as well. I have tried various adds and removes of the monitors with no luck.


I'm having a problem with Java. Why does the following code return null?  public class TestClass {     public String top,top1,top2,top3,top4;      public TestClass(){         changeTop(top);         changeTop(top1);     }      public void printTop(){         System.out.println(top);     }      public void changeTop(String reference){         reference="lolly";     }  }   When I run the following:   TestClass x =   new TestClass(); x.printTop();   It also returns null. I don't understand it because i thought I was passing a reference to the ChangeTop. How can I fix this? I want to give the name of the parameter to a method to change it.

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


Working on the book: Daniel J. Velleman. "HOW TO PROVE IT: A Structured Approach, Second Edition" (p. 127)  Theorem. For every real number x, if $x > 0$ then there is a real number $y$ such that $y(y + 1) = x$.  I will use the proof of this theorem to give context to my question. The skeleton of the proof is: Let $x$ be an arbitrary real number, and suppose $x > 0$. Let $$ y = \frac{-1+\sqrt{1+4x}}{2} $$ which is defined since $x > 0$. I often see that, in the middle of an Existential statement proof, the word "let" appears. I understand the justification for the statement "Let $x$ be an arbitrary real number, and suppose x > 0...", since the statement he is trying to prove has a Universal Quantifier. Variable $x$ needs to be arbitrary; otherwise, it wouldn't be possible to use Universal Introduction inference rule. However, I have two questions:  Is there some justification from a logic standpoint for the phrase "Let $ y = \frac{-1+\sqrt{1+4x}}{2} $...  If using a Natural Deduction system with identity, it is possible to use Identity Introduction at any point of a proof to introduce, for example, "3=3". But, in the former case, does it count as an abbreviation ? Is there some inference rule that allows the introduction of some statement like "Let $y = ...$" in the middle of a proof ?   I appreciate any insight into this matter.

In Velleman, How To Prove It?, we learn to prove a goal of the form $\exists x P(x)$ by extracting the existential quantifier from the goal, assigning a value to an arbitrary variable x and then deriving $\exists x P(x)$ from the introduced assumption. In the example below, to prove $\exists y[y+2x=0]$ (1), we assume $y$ and assign to it the value $-2x$ (2) and derive the goal from this assumption (3).  $\exists y[y+2x=0]$ $ [y=-2x]  \rightarrow  [y+2x=0]$ $ [y=-2x]  \space \land \exists y[y+2x=0] \rightarrow  [y+2x=0]$  I really do not understand how is it possible to assume the value assignment to y as one of the givens in the proof. Is a mathetical equality logically treated as a tautology, so that it can be unrestrictedly assumed in any proof?


Let $N \unlhd G$ and $U \le G$ with $G = NU$. Then there exists an inclusion-preserving bijection from the set of all subgroups $X$ with $U \le X \le G$ on the set of all $U$-invariant subgroups $Y$ with $U \cap N \le Y \le N$.   A subgroup $V \le G$ is called $U$-invariant for some subgroup $U \le G$, if $V^g = V$ for each $g \in U$.  It guess the map might be $\varphi(X) = X \cap N$, I could show injectivity by using the so called Dedekind identity (*) by which if $X \cap N = Y \cap N$ and factoring $X = U(X\cap N), Y = U(Y\cap N)$ we have $$ X = U(X\cap N) = U(Y\cap N) = Y. $$   But how to show surjectivity?  (*) The Dedekind identity as I know it goes like this, let $G = UV$ for two subgroups $U,V \le G$. Then every subgroup $H$ with $U \le H \le G$ has a factorisation $H = U(V\cap H)$.

Let $G$ be a finite group. Let $N \trianglelefteq G$ and $U \leq G$ such that $G = NU$. Then there exists a bijection, preserving inclusion, from the set of subgroups $X$ satisfying $U ≤ X ≤ G$ to the set of $U-$invariant subgroups $Y$ satisfying $U \cap N ≤ Y ≤ N$.  This is a problem from Kurzweil-Stellmacher book. I dont know how to do it. Thanks for any help.


This is a region dialect issue, while discussing local idiosyncrasies the question came up is the following sentence grammatically correct with or without the "to be"  "The clothes on the line need to be dried"  In Pittsburgh, the regional dialect causes the "to be" to be dropped from speech.  "The clothes on the line need dried"  Although understood by the community and speaker, is this valid english?

In the  (and possibly elsewhere), the following construction is possible:        This car needs washed. (=needs to be washed)   The room needs cleaned. (=needs to be cleaned)      It appears that, if a verb like needs is followed by a passive construction in the infinitive, the "to be" portion is left out.  This construction sounds so unnatural to my ear that I have no intuition as to the extent to which it can be extended to other words and contexts.  If anyone here is a native speaker of this dialect of English, perhaps they can help to explain the limits on its use.  My basic question is: how productive is this particular construction among those who use it?  To be more specific, can this construction be used with any verb (if that verb can be immediately followed by a passive construction, of course)?  That is, would (any of) the following be acceptable, for example?        At this restaurant, we always wait seated. (=wait to be seated)   My kid hates picked last in sports. (=hates to be picked)   We all want loved. (=want to be loved)      If this construction is restricted, then which verbs can be used, aside from need?  Edit: What I am really hoping for here is that there is someone who happens across this question that can say, "I actively use this construction, and here's what I can and can't say."


Are the sets $\varnothing$ and $\{\varnothing\}$ equal?

Herbert in his book "Elements of set theory" on page no 3 says that      we can form the set $ \{ \emptyset \} $ whose only member is $\emptyset $. Note that $ \{ \emptyset \} \neq  \emptyset $, because $ \emptyset \in \{ \emptyset \} $ but $\underline{ \emptyset \notin \emptyset} $·   By the last argument $\emptyset \notin \emptyset$, is he saying that empty set is not a member of or does not belong to empty set  OR  it is a typo and he wanted it to be $ \{\emptyset \} \notin \emptyset $, that set containing empty set is not a member of empty set


In order to answer this question, I want to sum up the probabilities for $1 \leq N \leq 14$:   $P(N<6)=0$ $P(N=6)=\displaystyle\frac{6!}{6^6}$ $P(N>6)=\displaystyle\frac{?}{6^N}$   Can you please advise on how to work out the third bullet?  Any suggestion for an alternative solution will also be appreciated.  Thanks

We roll a die until each side appears at least once, then we stop.     What is the probability of rolling exactly $n$ dice?   I guess the answer is  $$6-6\left(\dfrac{5}{6}\right)^n\;,$$  but this may be wrong.  In trying to solve this problem, I read , but I couldn't solve the problem.


What are the different properties of Complex Numbers. ?  I have doubt on real life use of complex numbers. Where and in what conditions do we use complex numbers in our day to day life.  My main focus is to know apart from Electrical ENgineering where it is used. Daily Life use. which can be understood by layman

I've always enjoyed solving problems in the complex numbers during my undergrad. However, I've always wondered where are they used and for what? In my domain (computer science) I've rarely seen it be used/applied and hence am curious.  So what practical applications of complex numbers exist and what are the ways in which complex  transformation helps address the problem that wasn't immediately addressable?  Way back in undergrad when I asked my professor this he mentioned that "the folks in mechanical and aerospace engineering use it a lot" but for what? (Don't other domains use it too?). I'm well aware of its use in Fourier analysis but that's the farthest I got to a 'real world application'. I'm sure that's not it.  PS: I'm not looking for the ability to make one problem easier to solve, but a bigger picture where the result of the complex analysis is used for something meaningful in the real world. A naive analogy is deciding the height of tower based on trigonometry. That's going from paper to the real world. Similarly, what is it that is analyzed in the complex world and the result is used in the real world without imaginaries clouding the problem?  The question:  is nice but covers a more mathematical perspective on interim results that make solving a problem easier. It covers different ground IMHO.


Is it possible to run multiple virtual machines on a virtual server? I am on a project and I want to run an Intrusion Detection System as distributed using many ubuntu virtual machines. Is it possible to be done on a virtual server which runs Ubuntu?

I've been playing with virtual machines lately, and I wondered if I could run a virtual machine inside a virtual machine.   Is this possible? Is it practical?


The calculation in cell I15 should result in 0 but instead it is 0,0000000000000000004336808.... Any idea why this happens? The calculation is pretty simple, just 0,00125574 - 0,00125574 Below is the sheet that I'm referring to:

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


According to the third law of Newton, every action has an equal and opposite reaction. This would (to me) suggest that every surface should put a force exactly opposite the weight of the body. If so, why does compression occur? Say you keep a weight on a sponge, then the sponge compresses, why is this?   Does the sponge not give an equal reaction to the weight on it?  Edit:   This question is different from this one because there the question is mainly about which bodies  the forces act on according to third law while the question I asked is mainly about compression and how much force a body applies against a weight put placed on it.

Newton's third law of motion states that every action has an equal and opposite reaction. That is the reason we do not sink into the earth, because when our weight exerts a force on the earth it also exerts an equal and opposite force on us.  But when we stand on quicksand or on fluids we can sink in. How is this possible? Does it not exert an equal and opposite force on us? Or are Newton's laws different in the case of fluids and substances of low densities?


Recently I installed GNUstep using this command   sudo apt-get install gnustep-gui-runtime   After I did this I saw this GNUstep folder as in the picture which contains nothing!  So I ran:   sudo apt remove gnustep-gui-runtime   and the folder is still there, and when I just delete the folder and refresh I see the folder is back again!

In my home directory there's a directory called “GNUstep”. As I don't use GNUstep I want to remove this directory, but it keeps being created when I do so:  $ tree GNUstep GNUstep └── Defaults 1 directory, 0 files $ rm -rf GNUstep $ tree GNUstep # executed after a few seconds GNUstep └── Defaults 1 directory, 0 files   I already removed every related package so that apt search gnustep | grep installed now doesn't show anything. I also did apt autoremove without any avail. I use Lubuntu 16.04.  How can I determine which process creates the directory every time I removed it, and how can I prevent it from doing so?  This is not a duplicate of:    – Other than “just delete it” (which I did) it contains no information about how to permanently remove the directory.  – I already did that and it didn't solve the problem.      suggests:     As a workaround you can change the value of GNUSTEP_USER_DEFAULTS_DIR in /etc/GNUstep/GNUstep.conf file.   Unfortunately there's no such file on my machine, not even /etc/GNUstep exists.


The software avidemux seems to be no longer available in Ubuntu 18.04.  The command   sudo apt install avidemux   gives the prompt  Reading package lists... Done Building dependency tree        Reading state information... Done Package avidemux is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'avidemux' has no installation candidate   So what is the GUI alternative of avidemux?

If just need to crop Audio/Video from a longer track, what can I use? I tried OpenShot, but I find the export video slow, perhaps its compling all the "layers" into a new movie? Perhaps I just need a simple "crop" tool for audio/video will surfice?


In php, what would be the better way to protect against malicious user input:    $password = trim($_POST['password']);   $password = strip_tags($password);   $password = htmlspecialchars($password);   Or   mysqli_real_escape_string(connection,$_POST['password']);   Or is there a even better way?

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?


The title says it really. Why is  so special?   I'm just curious as to how and why the term 'special' came to describe the theory of relativity where gravitational forces are negligible. I guess there was a need to distinguish it somehow from general relativity, but it still seems a slightly strange choice. Can anyone shed any light on the history of this?  Are there any versions of relativity that aren't special?

Initially I thought in  the velocity was constant, whereas  allowed treatment of accelerated frames as well.  But now I have heard that SR is only valid locally?


Is true that if $A\subseteq B$ then $\operatorname{interior}(A)\subseteq \operatorname{interior}(B)$, where $\operatorname{interior}(A)$ denotes the largest open set contained in $A$?

Please let me know if you find my proof satisfactory.  Let $A\subset B\subset \mathbb{R}^n$, where $\bar{A}$ is the closure of $A$.  If $\vec{x}\in \bar{A}$ then $\vec{x}\in A^\circ$ or $\vec{x}\in ∂A$ (in the boundary of $A$). If $\vec{x}\in A^\circ$ then $\vec{x}\in A \implies \vec{x}\in B\subset \bar{B}$. If $\vec{x} \in ∂A$ then $B_\varepsilon(\vec{x})\cap A\ne \emptyset \ne B_\varepsilon(\vec{x})\cap B$ (for any $\varepsilon > 0$). Thus, since $A\subset B$, $\vec{x}\in B \implies \bar{A}\subset \bar{B}$.


It seems like a particular dance is called "Two-step". It gave me some doubts about how to spell step in the description of a method I use. If my method has two steps, should it be called a two step method or a two steps method?

Why are year, pound and mile in the singular form in the phrases below?   five-year-old children  20 pound note 10 mile run   Is that because they're acting as adjectives, which are always invariable in English?  Is it incorrect to say...   five-years-old children? 20 pounds note? 10 miles run?


My model looks how I want it to as it is, but when I use subdivision surface seemingly random chunks get added or taken away. How can I prevent this?

How can I use the subdivision surface modifier to create more high poly meshes without ruining sharp edges? For example this mesh  The sphere should be subdivided but the rim of the cylinder should stay the same because it is a sharp edge. This is the result of the subdevision  How can I get sharp edges to not be affected by the sub surf mod?


I know this question has been asked before but the solution is always ntfsfix which ended up not working for me. The error message is:  Error mounting /dev/sda4 at /media/user/OS: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000" "/dev/sda4" "/media/samrat/OS"' exited with non-zero exit status 14: Windows is hibernated, refused to mount. Failed to mount '/dev/sda4': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.   I was trying to move something I downloaded on the Ubuntu partition to the windows partition so I need write privileges to do this. It's worked before but I suddenly got this error message. I booted into Windows 10 and made sure to shut down and boot into Ubuntu. Didn't work. ntfsfix didn't work and gave the following error message:  Mounting volume... Windows is hibernated, refused to mount. FAILED Attempting to correct errors...  Processing $MFT and $MFTMirr... Reading $MFT... OK Reading $MFTMirr... OK Comparing $MFTMirr to $MFT... OK Processing of $MFT and $MFTMirr completed successfully. Setting required flags on partition... OK Going to empty the journal ($LogFile)... OK Windows is hibernated, refused to mount. Remount failed: Operation not permitted

Whenever I boot Ubuntu, I get a message that it cannot mount my windows partition, and I can choose to either wait, skip or manually mount.  When I try to enter my Windows partition through Nautilus I get a message saying that this partition is hibernated and that I need to enter the file system and properly close it, something I have done with no problem so I don't know why this happens.    Here's my partition table, if any more data is needed please let me know.     Device Boot      Start         End      Blocks   Id  System /dev/sda1            2048    20000767     9999360   83  Linux /dev/sda2        20002814   478001151   228999169    5  Extended /dev/sda3   *   478001152   622532607    72265728    7  HPFS/NTFS/exFAT /dev/sda4       622532608   625141759     1304576   82  Linux swap / Solaris /dev/sda5        20002816   478001151   228999168   83  Linux


I am relatively new to Java and ML but have been trying to learn, so forgive any noob mistakes. I have been following an article about ML in python  have been trying to kind of translate it to Java to train the language and learn about the subject in the process, I have been getting a NullPointerException at the line of the variable loss and when I try to initialize the method in the main class, I can`t seem to find the problem.  I have tried running the method in a non static way and just rewriting everything, but it doesn`t seem to work.      public static double calcLoss() {         for (int i = 0; i < y_true.length; i++) {             double a = (1 / y_true.length) * Math.pow(y_true[i] - y_pred[i], 2);             loss = a;         }                return loss;     }   I know it says not to do it but here is a pastr  with the full code, maybe this helps.   This is the error  >Exception in thread "main" java.lang.NullPointerException     >at Net.Neuron.calcLoss(Neuron.java:40)     >at Net.Main.main(Main.java:28)

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


Before run yum remove ceph-release, I would like to look up ceph-release. But quotes like ' and " still brings results like ceph releases, release ceph. So how to look up exactly "ceph-release"?   That was just an example. I would like to know how to look up an exact phrase like "a-b", having punctuation in it.

I want to search for what += means, but Google won't return any documents.  Also when I come across some PHP code I don't understand I can't search for the keywords as written.  How can I search for these special characters or include these special characters in a search.


I can't install gnome-software, here is the error shown:- puloq@puloq-HP-Laptop-14s-dk0xxx:~$ sudo apt install gnome-software [sudo] password for puloq:  Reading package lists... Done Building dependency tree        Reading state information... Done Package gnome-software is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'gnome-software' has no installation candidate  Can someone please help?

There are now errors when updating and I cannot install most software due to a corrupted  /etc/apt/sources.list   file. Is there a copy I can download to replace it?  The file would be for Ubuntu 12.04 (Final Beta) in the United States.


I have a set of images that load from my solutions resource file, now they show up fine in design mode and in Blend but they won't show up at all when I actually run the program.  Here is the markup of the controls  <WrapPanel x:Name="heartsWrapPanel" Height="25.97" Canvas.Left="437.94" Canvas.Top="594.83" Width="75.26">     <Image x:Name="heart1" Height="22.388" Width="24.777" HorizontalAlignment="Left" VerticalAlignment="Bottom" Source="pack://siteoforigin:,,,/Resources/heart.png"/>     <Image x:Name="heart2" Height="22.388" Width="24.777" HorizontalAlignment="Left" VerticalAlignment="Bottom" Source="pack://siteoforigin:,,,/Resources/heart.png"/>     <Image x:Name="heart3" Height="22.388" Width="24.777" HorizontalAlignment="Left" VerticalAlignment="Bottom" Source="pack://siteoforigin:,,,/Resources/heart.png"/> </WrapPanel>   Now I can't figure out what's wrong, there's nothing wrong with the wrap panel as I've tried to put in other elements in it and they show up fine, and like I said the images show up in design mode and in Blend but it won't show up during runtime.

For a WPF application which will need 10 - 20 small icons and images for illustrative purposes, is storing these in the assembly as embedded resources the right way to go? If so, how do I specify in XAML that an Image control should load the image from an embedded resource?


I have a slide where I want to display two quotes with citations. I use \onslide to reveal one quote at a time with \footcite to display citations to the sources.   \documentclass[10pt,xcolor=dvipsnames, aspectratio=169]{beamer}  \usepackage[natbib=true, style=alphabetic, citestyle=authoryear,backend=biber]{biblatex} \addbibresource{refs.bib} \DeclareLanguageMapping{american}{american-apa} \begin{document}  \begin{frame}   \onslide<1->{     \begin{quote}        Quote 1 \footcite{palen_success_2015}.     \end{quote}   }   \vfill   \onslide<2->{     \begin{quote}       Quote 2 \footcite{crawford_what_2016}.     \end{quote}   } \end{frame} \end{document}   I want the citations to be displayed only when the quotes are displayed. However, the citations in the footnote appear on every slide.      How can I reveal the citations only when the footcite is displayed?  Edit I disagree that this question should be marked duplicate. When I was searching for an answer to my question, I did not find the proposed duplicate. Also, I think many people may not understand how the answer to that question can be used to solve the problem.  Even though both questions deal with the relationship between citations and only, they seem different enough to both exist.

The following Q&A is based on an answer I wanted to give for , but since a radical edit of the question, my answer does no longer fit, so I'm going to post it as a new question, in the hope it might be useful for someone else.   How to uncover \footfullcite step by step?


Sorry for the silly question, but I wonder how can I get an app I built (with cmake) listed in the dash. Immediately after the build completed, I moved into a /usr/lib/folder brand new folder. I thought that would have sufficed, but that's not the case.  I have read several posts about problems with Dash, but they all make reference to rebuilding because of potential problems. I could give them a go, but I'm not sure in first instance a simple file move is enough.  Any guidance?  Thanks

I just installed the lastest version of . I works fine but in order to use it, I have to enter the following in the terminal: cd ugene-1.11.5/ then execute ./ugene -ui to launch UGENE GUI.   This takes too long. I would like to build a .desktop file for UGENE to be used in Ubuntu 12.04 so that I can simply open it from the unity launcher.  Not sure if this is helpful but the website says: By default ugene script launches the command-line version of UGENE.  Here's what I have (not sure if it's right):  [Desktop Entry] Version=1.0 Name=my Unipro UGENE GenericName=Integrated Bioinformatics Suite Comment=Unipro UGENE is a cross-platform visual environment for DNA and protein sequence analysis. MimeType=text/english;text/plain;text/x-makefile;text/x-c++hdr;text/x-c++src;text/x-chdr;text/x-csrc;text/x-java;text/x-moc;text/x-pascal;text/x-tcl;text/x-tex;application/x-shellscript;text/x-c;text/x-c++; Exec=/home/samuel/ugene-1.11.5 ./ugene -ui -c %F Icon=/usr/share/icons/hicolor/scalable/apps/ugene.svg Type=Application Terminal=true Categories=Utility;Development; StartupWMClass=UGENE   I added the launcher named my Unipro UGENE to my unity bar and tried opening it but it doesn't appear. I must be missing something. I don't know what the StartWMCClass field is suppose to be nor do I know whether I entered the correct MimeType.


Since enhanced for loops are read only, it seems like each element is being copied into the new variable that you define when setting up the loop.  Is there an implicit statement here?  Maybe something like this:  int[] numbers = {1, 2, 3}; for(int number : numbers){   numbers = numbers[i]; // Implicit statement?  Problem: the i variable does not exist.   // Do stuff... }

Consider:  List<String> someList = new ArrayList<String>(); // add "monkey", "donkey", "skeleton key" to someList     for (String item : someList) {     System.out.println(item); }   What would the equivalent for loop look like without using the for each syntax?


I have an Ideapad Touch u430 that came with AOE licence. As it was recommanded, I used the Energy Manager to enable the Economy mode (I don't remember the exact name) that makes your battery stop charging at 59% for a long battery life. It's a Lenovo proprietary software. I installed Ubuntu and deleted windows for good. I didn't disable the Economy mode before making the switch. Ubuntu is working fine, but the battery still stops charging at 59%. It must be something in the bios. But I cannot find it.  Since the Lenovo Energy Manager is a proprietary software (a blotware that comes with the computer), I cannot study its code or show it to more experienced developers to reverse this very annoying action. I checked every available solution, they all involve going back to win8/Energy Manager. I cannot go back to Windows, I have no licence now. Even if I install it again, there is no chance to get the Lenovo softwares back.

I just learned that some Lenovo laptops include a utility that offers to limit battery charging capacity to within 0–80% in order to slow the attenuation of the battery lifespan:    How can I do this in Ubuntu?


Currently PureOS is installed on my computer. How do I replace it by Ubuntu? I tried with a bootable USB stick. The stick is not seen by the system. I can't even choose how it is being booted.

This is the third time I've tried to install Ubuntu Server 14.04.03 64-bit on the same laptop, and each time it caused different problems.  Each time I wrote the same iso image to a USB flash drive by using a different application and OS.   Universal USB Installer (pendrivelinux.com) from Windows WinImage writer from Windows built-in image writer from Linux Mint 17.2    The iso image is the same in all three cases, the USB flash drive is the same, and the laptop is the same. However each time the installation of Ubuntu gave me different installation options. For example, the last time I installed Ubuntu, it didn't show all the packages to choose while installing (Basic Ubuntu server, etc.).


In this post: , I am having difficulty understanding some of the steps. We have : (a) $s^2=\frac{1}{n-1}\sum_{i=1}^{\infty}(x_i-x\bar)^2$ and further down, (b) $E(s)= \sqrt\frac{\sigma^2}{n-1} E(\sqrt\frac{s^2(n-1)}{\sigma^2})$ I understand the 2nd and 3rd lines, but how do we get from (a) to (b)? (My knowledge of maths is basic)

According to the Wikipedia article on  the sample SD   $$s = \sqrt{\frac{1}{n-1} \sum_{i=1}^n (x_i - \overline{x})^2}$$  is a biased estimator of the SD of the population. It states that $E(\sqrt{s^2}) \neq \sqrt{E(s^2)}$.   NB. Random variables are independent and each $x_{i} \sim N(\mu,\sigma^{2})$   My question is two-fold:   What is the proof of the biasedness? How does one compute the expectation of the sample standard deviation    My knowledge of maths/stats is only intermediate.


I need to convert 500+ .xlsx files to .txt (or .csv). To do this I found . It works well if I write the command like this:  xlsx2csv fileA.xlsx fileA.txt   I have however been unable to run the command on all files (500+ files) in the current folder. Could you please help me with that?     I Know I had figured out how to do this some time ago (via google) and I have tried again today but I did not have any luck for the last hour. So please forgive me asking such a likely simple question.  Thanks for your Help.

I need to compile all of the C files in a directory into seperate outputs... see example gcc -Wall program1.c -o program1.out  How do I do this?


I have written java client server socket connection code. In that the server accepts the client connection, then the server sends the data using PrintStream , and client reads the data in readline(). After this, the client will wait for the server in readline. If there is a network disconnection, the client keeps waiting in the readline and never exits from readline. Is there is a way to detect the disconnection from client side itself? Or whether I have to write new heartbeat thread to check network disconnection?

Let's say I'm running a simple server and have accept()ed a connection from a client.  What is the best way to tell when the client has disconnected? Normally, a client is supposed to send a close command, but what if it disconnects manually or loses network connection altogether? How can the server detect or handle this?


I want to do step by step Cross-Validation using glmnet. For this I must have a vector with all variables from model.matrix.   For example, one of the R examples for model.matrix are:  dd <- data.frame(a = gl(3,4), b = gl(4,1,12))  options("contrasts") model.matrix(~ a + b, dd, contrasts = list(a = "contr.sum"))   This gives:     (Intercept) a1 a2 b2 b3 b4 1            1  1  0  0  0  0 2            1  1  0  1  0  0 3            1  1  0  0  1  0 4            1  1  0  0  0  1 5            1  0  1  0  0  0 6            1  0  1  1  0  0 7            1  0  1  0  1  0 8            1  0  1  0  0  1 9            1 -1 -1  0  0  0 10           1 -1 -1  1  0  0 11           1 -1 -1  0  1  0 12           1 -1 -1  0  0  1   But there are in total 3 variables of a and 4 variables of b. I also want these other variables a3 and b1. Because I will use this later for calculating the coefficients for a certain lambda:    x=model.matrix(~ a + b, dd, contrasts = list(a = "contr.sum")) y=sample(0:1,12,replace=TRUE) coef(glmnet(x,y,family="binomial"),s=0.01)  (Intercept)  2.900983 (Intercept)  .        a1           .        a2           .        b2          -2.128341 b3          -2.128577 b4          -2.128798   Questions:  1.Why are a3 and b1 not included in above variables? 2.Is it possible to include a3 and b1 in the designmatrix, such that these will also appear in the coefficients? 3.And if 2. is possible, is it then also a mathematically correct thing to do?

I am running an OLS regression using dummy variables built from categorical variables. Say, race became race1, race2 and race3. I omit race1 in order to escape the dummy variable trap and run OLS and gain some coefficients for race2 and race3.  What would be the coefficient for race1 in the regression equation? Or I just should not include the omitted dummy variable into the final equation to estimate the predicted value?


I was wondering to improve thumbnail size as you see here just in front page of template with some text (See ) and table via Blogger CSS.

It seems to be the  that tables should not be used for layout in HTML.   Why?  I have never (or rarely to be honest) seen good arguments for this. The usual answers are:   It's good to But this is a fallacious argument; . I guess it's true that using the table element for layout has little to do with tabular data. So what? Does my boss care? Do my users care?Perhaps me or my fellow developers who have to maintain a web page care... Is a table less maintainable? I think using a table is  than using divs and CSS.By the way... why is using a div or a span good separation of content from layout and a table not? Getting a good layout with only divs often requires a lot of nested divs. Readability of the codeI think it's the other way around. Most people understand HTML, few understand CSS. It's better for SEO not to use tablesWhy? Can anybody show some evidence that it is? Or a statement from Google that tables are discouraged from an SEO perspective? Tables are slower.An extra tbody element has to be inserted. This is peanuts for modern web browsers. Show me some benchmarks where the use of a table significantly slows down a page. A layout overhaul is easier without tables, see .Most web sites that need an upgrade need new content (HTML) as well. Scenarios where a new version of a web site only needs a new CSS file are not very likely. Zen Garden is a nice web site, but a bit theoretical. Not to mention its  of CSS.   I am really interested in good arguments to use divs + CSS instead of tables.


I've recently installed CKEditor 4 for Drupal 7 module and some of the toolbar's icons don't seem to show up.  They are: Add Media Media Teaser Break and YouTube (to name a few).  I've cleared the Drupal and Browser cache, but that hasn't helped. I've also ensured that I've got the right skins (reuploaded just in case). I tried multiple skins and these same buttons don't seem to want to appear.  Does anyone have any ideas for how to resolve this issue? Test thread is here.    (Note, I installed CKEditor because I needed an easy solution for users to upload multiple images when created a post so I'm not really attached to CKEditor if someone has a better idea. I was using TinyMCE with the WYSIWYG module)

I'm using Drupal CKEditor module 7.x-1.13 and CKEditor 4.3.2. Everything is installed and appears to work fine... except that there are some buttons that don't appear despite being configured to do so, notably "Select All" and the justify left/right/centre/justified buttons. Here are the buttons as configured:    And here are the buttons as they appear:


I came across the following code in c#:          semaphore.Wait();         {             HandleRateLimit(region);         }         semaphore.Release();   ()  I was wondering, do the brackets around the HandleRateLimit(...) call have any special meaning? If not, why would someone write code that way?

I mean other than using it when required for functions, classes, if, while, switch, try-catch.  I didn't know that it could be done like .  In the above link, Eli mentioned that "They use it to fold up their code in logical sections that don't fall into a function, class, loop, etc. that would usually be folded up."  What other uses are there besides those mentioned?   Is it a good idea to use curly braces to limit the scope of your variables and expand the scope only if required (working on a "need-to-access" basis)? Or is it actually silly?   How about using scopes just so that you can use the same variable names in different scopes but in the same bigger scope? Or is it a better practise to reuse the same variable (if you want to use the same variable name) and save on deallocating and allocating (I think some compilers can optimise on this?)? Or is it better to use different variable names altogether?


Can anyone help me with this question:  I know i asked a similar question not a while ago but i'm not able to understand how its possible. If anyone could give me a lot of examples instead of an answer.  I need to find the regular expression for this language: L=all words that have 00 or 11 but not both.  Thank you!

Can anyone help me with this question: I know it before, but I have tried to solve it myself and didnt succeed. what is the regular expression for this language: L=all words that have 00 or 11 but not both.  Thank you!


I've been reading some through some fan theories lately and I really feel like believing the fact the Plagueis somehow avoided his death and made it all the way through to TFA. I've seen some apparent pics of him on google images (yeah, I'm not really trying too hard here) and I can't deny that it looks a fair bit like what Snoke did in the film. I've only seen the film once so I might be completely wrong. Also, what are the chances that they actually are the same person?  Edit: in a way this could be a dupe. But honestly I'm just asking if plagueisis had any previous depictions (canon or not) and whether it could be said that they look convincingly similar.

In Episode III,  explains to Anakin the power of the Dark Side to save people from death. He mentions  - the Sith who discovered this. Sidious then claims he died, which seems odd, given that kind of power.   Then in Episode VII (The Force Awakens) we find a Sith Lord who has appeared from no where. There seems to be two loose ends that fit nicely together.   My question is: Is there evidence to suggest that Supreme Leader Snoke is Darth Plagueis?


I have arch linux on a SD card and I need to change a configuration file. I can only do it with my phone (Android 6.0 cyanogenmod based). Problem is that the file manager (I'm using cyanogenmod default file manager but I tried ES file manager too) tells me I don't have permission to do it even having my phone rooted and having granted it superuser powers. I suspect it's an SD card thing, maybe it's Android that respects the fact that the file is a system file which was created in another environment. What can I try to do? I chose to post here instead on android network because I thought the permission thing was more relevant to this section

I have a rooted  tablet and while browsing my files, i came along this folder: (./0/android/data) in the internal storage ... lets say (X-plore file browser) has the folder: (./0/android/data/x-plore).   For some reason, i wanted  to change the permissions for that program, instead of giving it the permissions: (reading, writing, executing) ... it will be (reading & executing).   The problem is it says (process failed, some file systems do not allow changing permissions) using Root browser or ES File Explorer (both with root access).  1- Why it says i can not change permissions although i have the root access already ?    2- Why it refers to a folder of an external application [(./0/android/data/x-plore)] as a system file ?


I'm supposed to solve $u_{xx}-3u_{xt}-4u_{tt}=0$ with initial conditions $u(x,0)=x^2$ and $u_t(x,0)=e^x$.   So I factored the problem into $(u_x-4u_t)(u_x + u_t)$ and set each equal to 0 and found the 2 solutions to be $(x,t)=f(x+t/4)$ and $u(x,t)=g(x-t)$  Then I get $u(x,t)=1/2[\phi(x+t/4) + \phi(x-4)]$ + 1/2c $\int_{x-t}^{x+t/4} e^{s} ds$  =1/2[$(x+t/4)^2 + (x-t)^2$] + 1/2c[$e^{x+t/4}-e^{x-t}$]  I multiply out the first part then and get a solution of:  1/2[$5/2xt-15/16t^2$]+1/2c[$e^{x+t/4}-e^{x-t}$]  But the book has a solution of $x^2 + t^2/4 + 4/5[e^{x+t/4}-e^{x-t}]$  I don't understand how they get 4/5 in front of the exponentials and how $1/2[\phi(x+t/4) + \phi(x-4)]$ turns into $x^2 + t^2/4$ .  Can anyone see where I went wrong?

Solve $$u_{xx}-3u_{xt}-4u_{tt}=0$$ where $u(x,0)=x^2$ and $u_t(x,0)=e^x$.  My workings so far: I have factored the differential equation in the following way: $$(\delta_x-4\delta_t)(\delta_x+\delta_t)=0$$ where $\delta_x=\frac{\delta}{\delta x}$ etc. Now if we let $v$ be the solution to $(\delta_x+\delta_t)u$ then we have the following two equations: \begin{eqnarray*} (\delta_x+\delta_t)u=u_x+u_t=v\\ (\delta_x-4\delta_t)v=v_x-4v_t=0 \end{eqnarray*} Now for $v$ we simply find $$v=h(t+4x)$$ where $h$ is an arbitrary function of one variable. Now what remains is find $u$ such that $$u_x+u_t=h(t+4x)$$ I am stuck here, I thought about making a change of variables $\zeta=x+t$ and $\eta=x-t$ and thus using the product rule to show that $u_x=u_{\zeta}+u_{\eta}$ and $u_t=u_{\zeta}-u_{\eta}$ and thus $u_x+u_t=2u_{\zeta}$ and we need to solve $$u_{\zeta}=h(t+4x)$$ (I left out the factor 2 because $h$ is an arbitrary function). Do I simply integrate now and conclude $$u=f(\zeta)h(t+4x)+g(\eta)=f(x+t)h(t+4x)+g(x-t)$$ This seems wrong to me...  Some help would be greatly appreciated!


I am writing a document which needs a multicols environment stretching over multiple pages. Moreover I am intending to use \thepage in the body of the environment. To be specific I need to know whether the page ist odd or even.   After getting some weird results I realized, that the multicols package does not seem to step the page counter, unless a manual \newpage is issued.   MWE:  \begin{filecontents*}{\jobname.xmpdata} \Title{title} \Author{author} \end{filecontents*} \documentclass[a4paper,11pt,twoside,parskip=half]{scrartcl}  \usepackage[x-1a]{pdfx} \usepackage[ngerman]{babel}  \usepackage{blindtext} \usepackage{multicol}  \begin{document}   \begin{multicols}{2}     \blindtext\\     \textbf{PAGE: \thepage}\\     \columnbreak     \blindtext\\     \textbf{PAGE: \thepage}\\     \blindtext     \blindtext     \blindtext\\     \textbf{PAGE: \thepage}\\     \blindtext     \newpage     \blindtext\\     \textbf{PAGE: \thepage}\\   \end{multicols} \end{document}   Thanks in advance for any help

I am writing (contributing to) a LuaLaTeX package where a Lua function is used to generate images that are inserted in the LaTeX document.   One piece of information we need is the current page number to determine if we're on an odd or even page (I know that this is not that trivial, and I know about some strategies beyond \thepage). We set a Lua variable when we're still in the LaTeX part, and so far this works pretty well.  However, now it turns out that the sequence of images we create may be distributed on several pages, and we would really like to reflect that because our images may behave differently on odd and even pages.  Basically what we have is a series of  tex.print('\\includegraphics{something}\\par')   statements, executed in a loop within one Lua function.  Now the question: is there any way to either directly detect a page change between two such graphics or repeatedly retrieve the current page within such a loop?  All the solutions I have found for determining current odd or even state are in LaTeX itself. I know how to use \directlua to retrieve a value for use in LaTeX, but is there a way to do the opposite - retrieve a LaTeX value from within LUa?  Edit: to respond to TeXnician's comment and answer: When I modify the example code so it produces repetitions of paragraphs it seems that the page counter won't get updated within one Lua chunk:  \documentclass{article}  \newcommand\printluapage{%     \directlua{for i = 1, 60 do tex.print(tex.count['c@page'])          tex.print([[\par]]) end} }  \begin{document} \printluapage  New command  \printluapage  New command  \printluapage \end{document}   The page number is only updated with each new call of \printluapage.


I tried to dual boot Windows and Ubuntu, but I can't switch back to Windows. I installed Ubuntu on a separate partition, but I can't seem to switch back to Windows, kind of like this situation:

I installed Windows on my computer, followed by an installation of Ubuntu. However, now I'm unable to boot into my Windows install.  What can I do to fix this?


Is wcf a viable REST solution?  It prevents you from using some special characters like # so requesting tag/c# does not work.  is there a work around, is this by design?

I have a WCF ATOM Feed Service using the WCF REST Toolkit with the following UriTemplate  [WebGet(UriTemplate = "{category}/?numItems={numItems}")] public Atom10FeedFormatter GetFeedByCategory(string category, int numItems)   Most cases work, the edge is when I try to load the feed based on the category with a # sign.  I am loading courses for category='C#' and all the service ever sees is 'C'.  Both of these links are doing that. Does anyone know if there is some special way to escape this character in for WCF?


For example, consider an airline company like AIR FRANC KLM.  It doesn't manifest steady growth to support the hope that share price  would be higher in the future. At the same time it doesn't  pay a  dividend. In addition to this, it's prone to risks like CoronaVirus.  And yet, people buy its shares.  This question may be a duplicate of  where  the answers  suppose that it's because the company will be more valuable in the future (like IT  companies).  I see the benefit of buying their shares right now because the company will recover from the Coronavirus and then selling them in the future  when the price is stable, I don't see any benefit in buying it.  But still, people do?  Am I missing something?

I read somewhere that companies are not required to pay dividends to shareholders (this is correct, yes?).   If so, then if company A never pays dividends to its shareholders, then what is the point of owning company A's stock? Surely the right to one vote for company A's Board can't be that valuable.   What is it that I'm missing?


Using Chrome on my Windows 10 machine.  This behavior was noticed while reviewing Latest Answers, First Posts, Low Quality Posts.  Tested this in two communities (Stack Overflow and PM Stack Exchange*).  Scrolling to the bottom of the page results in not being able to click any of the blue buttons.      I think that's a bug, but I might be wrong.  *In PM Stack Exchange i couldn't test LQP.

I was having a look at an old question of mine when I browsed the  from the timeline. I scrolled downwards and realized the Review completed panel comes along for the ride. While that might be , tags flowing over top of it as pictured below probably isn't.  Here's a .gif of the Question and Duplicate tabs flowing over it as well. Note that the timeline button also flows over. If vote buttons are present, they will also flow over it.  Reproduced on Chrome and Microsoft Edge. Update Per  by Tiago Martins Peres, this issue also happens in other Review types, namely Late Answers, First Posts and Low Quality Posts. In addition to that, it is causing the action buttons on reviews to become unclickable if you scroll low enough.  As a temporary workaround, you can use 's , which  this issue.


I create the following list of list containing False:  array=[[False] * 3] * 5   How can I change only value value?  array[1][0]='change only this'   Currently the result is   [['change only this', False, False],  ['change only this', False, False],  ['change only this', False, False],  ['change only this', False, False],  ['change only this', False, False]]   which is not desired. I understand each column is one single object [False] * 3]. How can I decouple them from each other. Do I need to make them immutable somehow?

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


It's kind of an interesting result.  Here is how render viewport should look on frame 1:    Here is what happens when I press F12:    It's like I have a second camera (although I don't) somewhere below. What is even weirder is that If I place the camera behind the wall...    it shows everything correctly (example cube is seen):    As you can see, my camera is following an object that is on Bezier curve WHILE being on Bezier curve (right) itself. This animation is working perfectly on rendered viewport but not if I use ctrl+F12. Just the same grey viewpoint.  What could be the issue?

Have Blender on about 4 machines rendering animations. Just spotted on one of the machines its rendering something different from the actual scene that I have setup.    Top window shows a different set of layers objects to whats actually being rendered in the rendering window below.  In my scene contents, layers objects 1-5 are not visible, but these are the ones that look like they are being rendered.  The only thing I can assume is that perhaps it might be because I did not save the document before clicking render, but I would not have expected that behaviour (you dont need to save your word document before printing it).  Can anyone confirm why this is happening?


If you can only measure either position and momentum in quantum mechanics how would one find the average value of $x^{2}p^{2}$ for an infinite square well?

I already derived a QM expectation value for ordinary momentum which is: $$ \langle p \rangle=  \int\limits_{-\infty}^{\infty} \overline{\Psi}  \left(- i\hbar\frac{d}{dx}\right) \Psi \, d x $$ And I can read clearly that operator for momentum equals $\widehat{p}=- i\hbar\frac{d}{dx}$. Is there an easy way to derive an expectation value for $\langle p^2 \rangle$ and its QM operator $\widehat{p^2}$?


There are examples I took from Murphy's English Grammar in Use, Unit 81B   the Carters' house Mr and Mrs Carter's house   I couldn't understand why the latter goes like that and not like "the Mr and Mrs Carter's house"  According to my logic "the" belongs to "house" and not to "Carters"

One of the answers to  question states that "We shall discuss it in our today's meeting"  is grammatically correct. To me, that sentence is clearly wrong. While in today's meeting is fine and in our today meeting is OKish (though at the very least clumsy), there's something about the possessive there (our today's) that makes it wrong for me. I would read that sentence as in our today's (as opposed to your today's) meeting. Similar to in our car's trunk where the our clearly modifies car and not trunk or car trunk, the our in our today's seems to be modifying today's and not meeting. So, my questions are i) is it actually grammatically wrong to say in our today's or is it just a question of usage? and ii) if it is indeed wrong, how can we explain its wrongness?


$$ \int_{0} ^ {\pi/4} \frac {\tan^2x}{1+x ^2} dx$$  I have tried using $x=\tan \theta$. But in my opinion i am finding that this might not be closed  form. Please help.

So one of the question on the MIT Integration bee has baffled me all day today $$\int_{0}^{\frac{\pi}{4}}\frac{\tan^2 x}{1+x^2}\text{d}x$$ I have tried a variety of things to do this, starting with Integration By Parts Part 1 $$\frac{\tan x-x}{1+x^2}\bigg\rvert_{0}^{\frac{\pi}{4}}-\int_{0}^{\frac{\pi}{4}}\frac{-2x(\tan x -x)}{\left (1+x^2 \right )^2}\text{d}x$$ which that second integral is not promising, so then we try Integration By Parts Part 2 $$\tan^{-1} x\tan^2 x\bigg\rvert_{0}^{\frac{\pi}{4}}-\int_{0}^{\frac{\pi}{4}}2\tan^{-1} x\tan x\sec^2 x\text{d}x$$ which also does not seem promising Trig Substitution $x=\tan\theta$ which results $$\int_{0}^{\tan^{-1}\frac{\pi}{4}}\tan^2 \left (\tan\theta\right )\text{d}\theta$$ which I think too simple to do anything with (which may or may not be a valid reason for stopping here) I had some ideas following this like power reducing $\tan^2 x=\frac{1-\cos 2x}{1+\cos 2x}$ which didn't spawn any new ideas. Then I thought maybe something could be done with differentiation under the integral but I could not figure out how to incorporate that. I also considered something with symmetry somehow which availed no results. I'm also fairly certain no indefinite integral exists. Now the answer MIT gave was $\frac{1}{3}$ but wolfram alpha gave $\approx$ .156503. Note  The integral I gave was a simplified version of the original here is the original in case someone can do something with it $$\int_{0}^{\frac{\pi}{4}}\frac{1-x^2+x^4-x^6...}{\cos^2 x+\cos^4 x+\cos^6 x...}\text{d}x$$ My simplification is verifiably correct, I'd prefer no complex analysis and this is from this  close .


This is a similar question to :  I'm trying to launch outlook from the mingw shell. I want to launch a new message window with the TOEMAIL and SUBJECT populated.  Here's what I've tried:  start Outlook //c ipm.note //m mailto:johndoe@domain.com&subject=Hello   This starts the new message window with the right TO address, but no subject. Also outputs  [1] 17960   I've also tried:  start Outlook //c ipm.note //m mailto:johndoe@domain.com/&subject=Hello   This starts the new message window with the TO address "johndoe@domain.com/", still no subject, and...  [2] 13764 [1]    Done         start Outlook //c ipm.note //m mailto:johndoe@domain.com   I've tried a couple other variations, but I think the main problem is I'm unable to escape the ampersand.  Anyone have any ideas?

I am trying something like:  set pwd = abc&123 echo password %pwd%   I get the result as...   '123' is not recognized as an internal or external command, operable program or batch file.  password abc   Is the system like this or is there an escape for such characters?


After a power outage my laptop fails to boot. I investigated the matter with a bunch of disk utilities and live CDs. The data is intact, and I made a backup copy of it. Nevertheless I'd like to restore the disk functioning, including booting of course, with as minimal efforts as possible. I know many experts suggest to recreate partitions anew, restore operating system anew, and reinstall software anew. This is hardly doable in my case (I don't even have all distribution kits). This is why I'd like to edit corrupted partition table in-place, and I need an advice which part exactly is problematic.  The disk contains 2 volumes: one is primary partition and the other is a logical drive in extended partition.  When I boot the laptop from a live CD, Windows sees both drives, but the logical drive in the extended partition is inaccessible.  diskpart's command list volume shows that the volume fs flag is RAW instead of NTFS. The odd thing is that disk utilities which I used to restore data (including ) see this volume as NTFS and read data from it without problems.  Here is the output of diskpart:    And here's what DMDE shows:    The question is which raw bytes and how should I edit in the table (I can use DMDE for direct disk edition, for example) to make the volume proper NTFS accessible from Windows?  I'm not sure which other details may be important and ready to provide them upon request.  Update  The only one real answer among the linked ones suggests using TestDisk. First, I must say that this utility is very picky about OS - it does not run on any WinPE based live CD I tried. Finally I managed to run it on [almost] fully fledged Win7 live CD. Here is what it shows (please note NTFS in the logical volume in the extended partition):    and (please note FAT32 this time):    I need to recover the largest volume from here. It's displayed as FAT32 under TestDisk (DMDE shown NTFS). P command does not produce a readable list of files for this volume. I tried the T command to change type to NTFS, but this did not solve the problem: P still lists a garbage ("file system may be damaged"). Yet I see the full filesystem under DMDE and saved it using r.saver utility.  I ran a deeper search:    and found:    The Deleted NTFS volume is the actual drive with my data. Then I changed its from 'D' to 'L' and did Write changes to the disk and reboot.    The drive is still inaccessible, but now if I run DMDE it complains that MBR records require a disk of at least 625153410 LBA (320GB), but the disk is 625142448 LBA (320GB).  From my experience either TestDisk is incapable of doing the job in my case, or I need more detailed instructions what exactly to fix using TestDisk.  Thanks in advance.  As a small remark I must say that TestDisk is buggy: i made a backup of the partition table by corresponding TestDisk's command, then changed the table and wrote it to the disk; then discovered that the changes did not help and decided to rollback the changes from the backup - as a result I got completely different and incorrect partition table. The only thing that saved me from a fiasco was that I made another backup using dmde, which restored the structure as expected.

I've resized my C:\ partition but now I can't boot anymore. I tried to use CHKDSK to analyse the disk but keep getting this error:      CHKDSK does not support RAW disk.    I suppose the partition is damaged or changed to RAW format. So, how can I restore it to NTFS or at least recover my data?


For the inner product space $M_{2\times2} (\Bbb{C})$, with inner product $\langle A,B\rangle = \operatorname{tr}(AB^*)$, find the angle between $$A=\begin{bmatrix}2+i&1\\-1&0\end{bmatrix} $$ $$B=\begin{bmatrix}3-2i&1+i\\0&-1\end{bmatrix}$$  I tried to use $$\cos(z)=\frac{\langle A,B\rangle}{\|A\|\|B\|}=\frac{5+6i}{4\sqrt{7}}$$ but how can I find the angle? is it supposed to be a real number?

Let $\left<\;,\;\right>$ be an inner product defined by $\left<A,B\right>=$ tr$\left(A\overline{B}^{T}\right)$ over $M_n\left(\mathbb{C}\right).$  I am looking for the angle between: $$A=\begin{pmatrix}2+i & 1\\-1&0\end{pmatrix}\quad B=\begin{pmatrix}3-2i & 1+i\\0 & -i\end{pmatrix}$$  First we can see that:$$\overline{A}=\begin{pmatrix}2-i & 1\\-1&0\end{pmatrix}\quad \overline{B}=\begin{pmatrix}3+2i & 1-i\\0 & i\end{pmatrix}$$  $$\Downarrow$$  $$\overline{A}^T=\begin{pmatrix}2-i & -1\\1&0\end{pmatrix}\quad \overline{B}^T=\begin{pmatrix}3+2i & 0\\1-i & i\end{pmatrix}$$  And therefore:   $\left<A,B\right>=$ tr$\left(A\overline{B}^{T}\right)=\left(2+i\right)\left(3+2i\right)+1-i=5+6i$ $\left<A,A\right>=\left(2+i\right)\left(2-i\right)+1+1=7$ $\left<B,B\right>=\left(3-2i\right)\left(3+2i\right)+\left(1+i\right)\left(1-i\right)+1=16$   Now as the angle between any two vectors is defined we get that: $$\cos{\alpha}=\frac{\left<A,B\right>}{\Vert{A}\Vert\Vert{B}\Vert}=\frac{5+6i}{\sqrt{112}}$$  $$\Downarrow$$  $$\alpha = \;?$$  I didn't even know a complex number could be an image for the cosine function.  Thanks for any help.


I'm a novice photoshop user, i stumbled upon the designs of the awesome mike of creativemints, and i noticed how his backgrounds are really beautiful and smooth, i tried to recreate it and failed miserably so my question is, how do you achieve such effect??     and thank you so much!!

I have seen an image with this background. As a newbie I am unable to get this multi colored mixed background. I am able to get just two colors and that too linearly with the Blend Tool. But that doesn't look like this at all. Can some one please suggest me on how to achieve this in GIMP or in Photoshop?


I have only build a wordpress on vps,to test the Requests per second with ab command.  ab -n 500 -k -c 50 http://www.mynet/ Server Software: Apache/2.4.6 Server Hostname: www.mynet Server Port: 80  Concurrency Level: 50 Time taken for tests: 65.799 seconds Complete requests: 500 Failed requests: 0 Non-2xx responses: 500 Keep-Alive requests: 0 Total transferred: 123500 bytes HTML transferred: 0 bytes Requests per second: 7.60 [#/sec] (mean) Time per request: 6579.858 [ms] (mean) Time per request: 131.597 [ms] (mean, across all concurrent requests) Transfer rate: 1.83 [Kbytes/sec] received   I have tested for many times . Requests per second take values from 7 till 10. Time per request take values from 6000[ms] till 10000[ms].    The cpu and memory is below 5% as top command show. Poor performance of vps ?

This is a  about capacity planning for web sites. Related:      What are some recommended tools and methods of capacity planning for web sites and web-applications? Please feel free to describe different tools and techniques for different web-servers, frameworks, etc., as well as best-practices that apply to web servers in general.


I was searching outlier removal in R and I saw some comments related to almost never you should remove outlier from dataset. I wonder when we should remove outlier? I have a dataset consisting outliers because of over pricing of sellers in house prices. I think they are making my data noisy.Should I remove them with R programming? I know that if I have large enough dataset maybe they become less important right? but now I have a small dataset with categorical and numeric values. And which methods in R I can use?  Thank you

I am performing multiple regression analyses and I am not sure whether outliers in my data should be deleted. The data I am concerned about appear as "circles" on the SPSS boxplots, however there are no asterisks (which makes me think they are not 'that bad'). The cases I am concerned about do appear under the "casewise diagnostics" table in the output - therefore should I delete these cases?


If I understand it correctly, temperature is the measure of the average kinetic energy of a substance. Why is it then that $T\neq \bar E_{k}$ or something similar? Why is the kelvin a base unit and temperature a base quantity in The International System of Units (SI)?

I had always thought that temperature of a substance was a measure of the average kinetic energy of the particles in that substance:  $E_k = (3/2) k_bT $   where $E_k$ is the average kinetic energy of a molecule, $k_b$ Boltzmann's constant, and $T$ the temperature. (I'm not sure of the 3/2 coefficient.) Then I heard from several folks that this is a simplistic notion, not strictly true, but they didn't explained what they thought was flawed with this idea. I'd like to know what (if anything) is objectionable about this idea? Is it that the system must be macroscopically at rest? Is it that it ignores the quantum mechanically required motion of particles that persists at low temperatures? When is it not valid?


I want to give look to my Ubuntu like Windows 10, so I have downloaded the  from gnome-look.org, but I don't know how to install or apply it.

I have been using the default Ubuntu 11.10 with Unity for some time now and decided to start customizing it.  I have already been able to make some changes with the gnome-tweak-tool. However, there are many themes that I get from gnome-look.org that don't appear in the gnome-tweak-tool even after putting them in the /usr/share/themes folder.  Any idea why this is happening? Thanks.


I want to pass directory as a command line argument to the shell script.  #!/bin/bash   sourcedir=/home/dir/data  cd $sourcedir   find "$PWD" -maxdepth 2 -name \*_R1*.fastq.gz > list1  fastq_list=$sourcedir/list1 echo `cat $fastq_list` num_files=$(wc -l <   $sourcedir/list1) echo $num_files    cat > run_array_job.sh<<'EOF'  #!/bin/bash -l #$ -j y #$ -cwd -S /bin/sh #$ -l h_vmem=10G #$ -pe smp 12  if [ -z "${SGE_TASK_ID}" ]; then   echo "Need to set SGE_TASK_ID"   exit 1 fi    BASEDIR=/home/dir/data   echo "BASEDIR" echo $BASEDIR   BASEFILES=$( ls *_R1.fastq.gz)  BASEFILES_ARRAY=(${BASEFILES})  BASEFILE=${BASEFILES_ARRAY[(${SGE_TASK_ID} - 1)]}  echo $BASEFILE    ...................  ...................   EOF   qsub -t 1-${num_files}  run_array_job.sh   This array script for SGE cluster is script.sh and I am running it using    bash script.sh   However I want to pass the directory which is /home/dir/data from the command line such as below (instead of using it twice in the script)   bash script.sh /home/dir/data   I am not able to do that.

I know that shell scripts just run commands as if they were executed in at the command prompt.  I'd like to be able to run shell scripts as if they were functions... That is, taking an input value or string into the script.  How do I approach doing this?


A fair, 6-sided die is rolled 6 times independently. Assume that the results of the different rolls are independent. Let $(a_1,\ldots,a_6)$ denote a typical outcome, where each $a_i$ belongs to $\{1,\ldots,6\}$.  For any outcome $\omega=(a_1,\ldots,a_6)$, let $R(\omega)$ be the set $\{a_1,\ldots,a_6\}$; this is the set of numbers that showed up at least once in the different rolls. For example, if $\omega=(2,2,5,2,3,5)$, then $R(\omega)=\{2,3,5\}$.  Find the probability that $R(\omega)$ has exactly two elements. (Answer with at least 3 decimal digits.)  Find the probability that $R(\omega)$ has exactly three elements.  can anyone clarify or make hints for answer

A fair $6$-sided die is rolled $6$ times independently. For any outcome, this is the set of numbers that showed up at least once in the different rolls. For example, the outcome is $(2,3,3,3,5,5)$, the element set is $\{2,3,5\}$. What is the probability the element set has exactly $2$ elements? how about $3$ elements?   I know the sample space is $6^6$. The counting for $2$ elements is $6C2 \cdot 6!$? I would really appreciate the help! :)


#!/bin/bash var=1 if [[ $var -eq 0 ]] then     echo "No students" elif [[ $var -eq 1 ]] then     echo "1 student" elif [[ $var -eq 2]] then     echo "2 students" elif [[ $var -eq 3 ]] then      echo "3 students" elif [[ $var -eq 4 ]] then     echo "4 students" else     echo "A lot of students" fi   I've written this bash script . But it throws this error:   Failed test #1. Runtime error: main.sh: line 11: syntax error in conditional expression main.sh: line 12: syntax error near `then' main.sh: line 12: `then'

I'm completely new to Bash, and I'm trying to make a simple script to automate Git pulling and pushing from a repo, but I can't get it to work.  Here is a pastebin of the code:   #!/bin/bash #Git Puller / Pusher for MobArenaBattles  echo "Please type whether you want to pull or push:"  read proc cd $HOME/Desktop/IdeaProjects/Plugins/MobArenaBattles  if ["$proc"="push"]; then   echo "Please type the commit message:"   read message   git status   git add -A   git commit -m $message   git push elif ["$proc"="pull"]; then   git status   git pull else   echo "Invalid choice! Exiting." fi   The error I get is:  ./MAB Git.sh: line 9: [push=push]: command not found ./MAB Git.sh: line 16: [push=pull]: command not found   I have tried using == and -eq but it comes up with the same error. Sorry if I'm being stupid, it's my first attempt.  Thanks in advance.


I am using python to extract Emails from web using re library. it does its job but it extracts links that match the pattern. For example: /images/paramproofs/services/pgp/logo_black_16@2x.png /images/paramproofs/services/twitter/logo_black_16@2x.png /images/paramproofs/services/github/logo_black_16@2x.png /images/paramproofs/services/reddit/logo_black_16@2x.png /images/paramproofs/services/web/logo_black_16@2x.png /images/paramproofs/services/web/logo_black_16@2x.png /images/paramproofs/services/stellar/logo_black_16@2x.png /images/badges/install-badge-windows-168-56@2x.png /images/badges/install-badge-windows-168-56@3x.png  This is the pattern I use: (?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-z0-9](?:[ a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])

Over the years I have slowly developed a  that validates MOST email addresses correctly, assuming they don't use an IP address as the server part.  I use it in several PHP programs, and it works most of the time.  However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I realized that I wasn't allowing 4-character TLDs).  What is the best regular expression you have or have seen for validating emails?  I've seen several solutions that use functions that use several shorter expressions, but I'd rather have one long complex expression in a simple function instead of several short expression in a more complex function.


When I search on Stack Overflow, I get questions and answers. Unfortunately, I can only see the tags associated to questions. When an answer has been matched,     I think it makes sense to see the tags associated with the question to which the answer was given.  Moreover, we are able to see the title of the questions, and not the tags, whereas title and tags are extremely coupled (we doesn't allow the name of the langage in the title, because we want it in the tags).

When I perform a search, the result entries display the relevant tags, but only if it is a question link. If it's an answer link, there are no tags displayed. Sometimes I can easily infer the language, platform or technology, by reading the title and the excerpt -- but sometimes not, requiring me a visit to the question page. I suggest that when answers are displayed as search result entries, these entries include the tags of the parent question.


Suppose I want to do a search to find out if I have a file that matches the sha256 generated from the file test1.txtusing the command:  sha256sum -b test1.txt   I get as output:  e3d748fdf10adca15c96d77a38aa0447fa87af9c297cb0b75e314cc313367daf * test1.txt   So, I want to find the files that match the checksum generated instead of using the name.  Is this possible?

I have the md5sum of a file and I don't know where it is on my system.  Is there any easy option of find to identify a file based on its md5? Or do I need to develop a small script ?  I'm working on AIX 6 without the GNU tools.


I want to write a review article in a particular narrow area of interest as part of my Doctoral research. But there is already a review article on that area published 2 years ago. So can I write a review paper on that area ?

Suppose that a systematic review on a topic X was published some (3-8) years ago by someone else, and it is currently still a useful source for what has been made before it was published. However, more recent works were also published later.  Generally, how can I decide whether it is a good idea to work on a newer systematic review for publication, taking into account that the newer review could be (somewhat) similar in methodology and would be based on extended and more recent literature (including that already reviewed in the published one)?


For an English short story one of my sentences has the word which, but I'm not sure if i need a comma. Here's the sentence..... "He was stopped at his locker which of course happened to be right beside mine so I figured I might as well ask." Also, are there any other grammar things I could fix?

There are many 'rules' on the net saying that a comma should be placed before the relative pronoun 'which' in a non-restrictive clause. ()  But would the sentence have the same meaning without the comma before the relative pronoun?  Does omitting a comma before a relative pronoun change a nonrestrictive clause into a restrictive clause?  For example:  'We ate the pizza, which was nice.'  'We ate the pizza which was nice.'  If so does the same apply to relative pronouns other than 'which'?


I see there are many questions with this title, but this one is different, so please give it due thought:  Is time travel possible? If so, Can we go both forwards and backwards in time?  Paradox:  I am studying for a very competitive exam, wherein I must put in a LOT of effort to hope for any success. Now, I am lazy. And assume that time travel is possible, and I have access to it.  I decide to check my future, and (god-permitting) I see that I have passed with flying colors. Now, I "come back in time" and enjoy life, and don't study. So, it is just Impossible that I succeed. So, where is the flaw??  Does this prove that time travel must not exist, and will not exist?

I read somewhere that according to relativity, it is possible - involving black holes and other stuff - to jump into the past. Is it possible for anything to go back in time either continuously or by jumping?


We are using ubuntu server, and I have to move folders from one server to another server:     Folders: /var/www/html/demo5/site/app to /var/www/html/1/10/site   (Where app is the folder name)      Hostnames: 123.123 to host 456.456      Usernames: abc    to username : xyz   I have SSH access, but I am new to these commands.  I have already tried , but I didn't get it to work as I am new to commands.

I am trying to copy a folder to remote Ubuntu server using command line ssh connection, i understand it's doable to transfer a file using scp but i have many files in a folder iam trying to copy to that remote server, how is that done? anyone?  Thank you.


Any ideas about how to show this neatly? I have seen a way using inequality between geometric and arithmetic mean. Is there a simpler way?

given a sequence $a_n=a^{\frac{1}{n}}$ for $n\in\mathbb{N}^*$, $a\in\mathbb{R},a>1$ then proof that $\lim\limits_{n\to+\infty}a_n=1$ by definition.   proof:  given $a_n=a^{\frac{1}{n}}$ for $a\in\mathbb{R},a>1$.  for $n\in\mathbb{N}^*,n+1>n\Rightarrow \frac{1}{n+1}<\frac{1}{n}$ and because $a>1$ we gets $a^{\frac{1}{n+1}}<a^{\frac{1}{n}}$, since $\frac{1}{n+1}>0$, then $1=a^{0}<a^{\frac{1}{n+1}}<a^{\frac{1}{n}}\Rightarrow 1<a_{n+1}<a_{n}$.  then we proof that $\lim\limits_{n\to+\infty}a_n=1$ we need to show that $\forall\epsilon>0,\exists N,\forall n>N,|a_n-1|<\epsilon$  then for $\epsilon>0$, choose $N=\frac{1}{\log_a(\epsilon+1)}$, since $a>1$ we gets that $$\forall n>N,1<a^{\frac{1}{n}}<a^\frac{1}{N}\Rightarrow0<a^{\frac{1}{n}}-1<a^{\frac{1}{N}}-1\Rightarrow |a^{\frac{1}{n}}-1|<|a^{\frac{1}{N}}-1|=|a^{\log_a(\epsilon+1)}-1|=|\epsilon+1-1|=\epsilon\Rightarrow |a^{\frac{1}{n}}-1|<\epsilon$$  wich implies that $\lim\limits_{n\to+\infty}a_n=1\square$  my proof to the limit is correct?


$\frac{1} {\sqrt 1} + \frac{1} {\sqrt2} + \dots + \frac{1} {\sqrt{ 100}}$  Just bear in mind that I'm going to say the solution to a person of low education. So please provide creative hints or solutions. I don't want to use derivatives or other limit-related stuff. Thanks in advance.  EDIT:Sorry for posting a duplicate question but I have another question now.Can you prove that the series above does not have rational answer?

$$ \left\lfloor\frac{1}{\sqrt{1}} + \frac{1}{\sqrt{2}} +\dots+ \frac{1}{\sqrt{100}}\right\rfloor =\,? $$   I rationalized the denominator and then I think I should somehow group the numbers, but i don't know how.  Thanks in advance!


I have the following code in my MainActivity.java class:  private NavigationView nvDrawer;  @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          // Set a Toolbar to replace the ActionBar.         toolbar = (Toolbar) findViewById(R.id.toolbar);         setSupportActionBar(toolbar);          // Find our drawer view         mDrawer = (DrawerLayout) findViewById(R.id.drawer_layout);          // Setup drawer view         setupDrawerContent(nvDrawer);     }  private void setupDrawerContent(NavigationView navigationView) {          navigationView.setNavigationItemSelectedListener(                 new NavigationView.OnNavigationItemSelectedListener() {                     @Override                     public boolean onNavigationItemSelected(MenuItem menuItem) {                         selectDrawerItem(menuItem);                         return true;                     }                 });     }   The output of the LogCat states the following:   Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.design.widget.NavigationView.setNavigationItemSelectedListener(android.support.design.widget.NavigationView$OnNavigationItemSelectedListener)' on a null object reference         at com.gamecodeschool.fragmentnavigationdrawer.MainActivity.setupDrawerContent(MainActivity.java:54)         at com.gamecodeschool.fragmentnavigationdrawer.MainActivity.onCreate(MainActivity.java:37)         at android.app.Activity.performCreate(Activity.java:6237)         at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)          at android.app.ActivityThread.-wrap11(ActivityThread.java)          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)          at android.os.Handler.dispatchMessage(Handler.java:102)          at android.os.Looper.loop(Looper.java:148)          at android.app.ActivityThread.main(ActivityThread.java:5417)          at java.lang.reflect.Method.invoke(Native Method)          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)   So, the navigationView argument passed to the setupDrawerContent() method is a null object and calling the listener method on it causes this exception. Any suggestions how I could fix this problem?

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I have a CentOS 6.4 64Bit Dedicated server used for hosting several websites. I recently checked the traffic graph for my server and discovered that the inbound traffic is very high (about 200-500 Mbit). I don't download anything and I have absolutely no idea why is the traffic so high. the inbound traffic is 200GB already but the HDD doesn't fill up with information. I checked for HTTP DDos but everything seems regular.  Some info:  RAM Usage: 20% CPU Load: 50%  Services in the server:   Apache (local usage only) Nginx (as proxy server) mySQL exim ftp(pure-ftpd) SSH   Allowed ports in csf:  TCP_IN: 20,22,80,2083,2087,21 TCP_OUT: 20,21,22,25,37,43,80,110,113,443,587,873,2086,2087,2089,2703  UDP_IN: 20,21 UDP_OUT: 20,21,113,123,873,6277,53  ICMP_IN is disabled.  Traffic graph:   I would appreciate any help. Thanks.  EDIT  I was attacked by DNS DDos Amplification    I was attacked by DNS DDos Amplification

This is a  about DoS and DDoS mitigation.   I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth.  Nobody can access my site because all the requests time out, and I can't even log into the server because SSH times out too!  This has happened a couple times before, and each time it's lasted a couple hours and gone away on its own.  Occasionally, my website has another distinct but related problem: my server's load average (which is usually around .25) rockets up to 20 or more and nobody can access my site just the same as the other case.  It also goes away after a few hours.  Restarting my server doesn't help; what can I do to make my site accessible again, and what is happening?  Relatedly, I found once that for a day or two, every time I started my service, it got a connection from a particular IP address and then crashed.  As soon as I started it up again, this happened again and it crashed again.  How is that similar, and what can I do about it?


If one particle is dependent on the other how can an action on one particle affect the state of another if when you measure a particle, the result you see is based off of something that technically hasn't happened yet?

What ever happened to  in entangled quantum states, i.e. the ? I thought they argued that in principle one could communicate faster than speed of light with entangled, separated states when one wave function gets collapsed. I imagine this paradox has been resolved, but I don't know the reference.


Background  My professor assigned me a project as part of a course.  and has several flaws. I explained the problems of the project to my professor. However, the professor seems to believe that I just don't understand the project and don't know how to code.  The professor now sent the other student on a work trip for seven or eight months, starting in 10 days.  In the meantime, the professor asked me to fix the project and produce the results.  Unfortunately, the project is so flawed that I can't produce results with it. I believe that it's the other student's responsibility to fix the project. S/he also knows the project and it's issues much better than I do.  The professor still doesn't consider my concerns and just pushes me to finish the project. He wants to grade the course based on a publishable paper from this flawed project. (My other classmates already have required information to design a controller, and assigning this flawed project and grading like this is not fair.) Meanwhile, the professor does not even want to talk about a topic for my own thesis. I feel taken advantage of and don't know what to do.  Questions  What can I do to convince the professor that I should no longer waste time on another student's broken project but rather start my own? Would it be okay to refuse to work on this project?

Last semester, I took a course with my supervisor and he assigned me a project. This project is part of one of his student's theses. I did the project and passed the course.   Later, I was asked to upload my code for use in a paper. It turned out that the data the grad student had generated was not appropriate, and he needed to do other experiments. It later turned out there were other problems with the underlying model, and I redid a lot of that work as well.  The problem is that this other student is not really contributing at all.    Sometimes he does not come to work at all On one occasion the professor assigned us to do something, and he immediately told me he had no idea how to do it In one of our meetings with the professor, he talked 2 minutes with the prof with no slides; I talked for the other 58 with slides.    What should I do in this situation? I could not work like this, I have my own project and my thesis and stuff. I cannot dedicate my self for another student's thesis.  Question 1: how should I make this student understand this is his thesis and he should work more than me?  Question 2: How can I get off this project? I am taking another course with my supervisor, he again assigned me a term project with the same system and same grad student. I do not want to keep going like this. What should I tell to my supervisor Due to the problems we found, I think this current system is a bit of a dead end. But, I do not want to lose my connection with my supervisor; he is a good man.


How can I get rid of the metallic taste of canned tomatoes? I’m making salsa and needed extra tomatoes. I decided to use some canned tomatoes. Now my salsa has a metallic taste. Please help.

I used some canned tomatoes to make chili, which normally works fine, but today it has a really strong metallic flavor. From what I can tell, this is just because they're probably low-quality, so I won't be using this brand again.  Anyway, is there anything I can do to save this chili? I didn't notice the flavor until I added everything else.


If we have a number $X\sim f(x|\lambda)$ where $$f(x|\lambda) = \lambda e^{\lambda x}, x \geq 0$$ then $\sqrt{X} \sim r(y|\sigma)$ where $$r(y|\sigma) = \frac{y}{\sigma^{2}} e^{-y^{2} /(2 \sigma^{2})}, y \geq 0$$ which is the Rayleigh distribution. Why is this the case? It is easy to prove this mathematically with the transformation technique, as shown , but I'd like to have a more intuitive understanding on why this arises. For example the emergence of the Rayleigh distribution can be readily explained by considering the absolute value of two normally, uncorrelated vector components.

We have ground-truth data $\mathbf{x}^* = (0,0)^T \in \mathbb{R}^{2}$. Furthermore, we have $N$ measurements $\mathbf{x}_i \in \mathbb{R}^{2}, i\in \{1,\ldots,N\}$. We calculate the $N$ error vectors $\mathbf{e}_i = \mathbf{x}_i - \mathbf{x}^*$. We assume that the two components of $\mathbf{e}_i = (e_{x,i}, e_{y,i})^T $ are independent of each other and normally distributed with equal mean $\mathbf{\mu} = (0,0)^T$ and variance $\sigma^2$. The absolute errors $e_i = \sqrt {e_{x,i}^2 + {e}_{y,i}^2} $ follow a Rayleigh distribution, is that correct?  The probability density function (PDF) of the Rayleigh function is zero at a value of zero. Why is this the case (intuitively)? I would assume that our errors should most likely be 0 (i.e. PDF should be highest at 0)...


I have two internet connection from two different ISP. ADSL on eth0 and 4G on wlan0. Is there any way that if one ISP fails, the other take over automatically without a physical router and by Host OS (Ubuntu 18.04)?

is it possible to bridge more than 2 isp provider using pfsense? what router or device can bridge 2 or more isp providers in a router? i am planning to bridge at lease 5 isp providers to create a very good internet connection, what can i do to link all 5 providers in 1 router?


First player has Ace Seven.  Second player has Ace Seven.  Third Player has pocket Jacks.  Community cards are A J 5 5 5.  What is the winning hand in this situation?

I was playing Texas Holdem last night with some friends at my house and this was the hand we were dealt:  My cards 7♠ 6♦  His cards 10♠ 7♥  Cards on table  6♠ 8♠ Q♠ J♠ 2♠  Odd hand. Everyone else folded after the flop. Who would have won?  My arguments, 1. Because there is a flush on the table our pocket cards are void and we split the pot. 2. Because the Queen is the highest ♠ card on the table it is shared by both of us so we split the pot. I thought that in a flush the only card that matters is the highest for example if he had a pocket K♠ he would have won.   His argument, was that since his 10♠ is higher then my 7♠ he won and takes it all.  We were all confused and the vote between players was split 50/50 so i said house rules and split the pot. He got pissed and left the table and didn't come back. Was i in the wrong? Any help is appreciated.


I've never really liked this feature about Win7, but I guess I just got used to it. The feature I don't like is mousing over the Win7 icons when there are multiple windows of the same type open. You have to waste that extra time choosing the window after it pops up and it's just clunky.  The XP taskbar was nice, because you didn't have to go through any of this, but it had the problem where you ran out of taskbar space fast. I often resized my taskbar to take care of this. However, on Windows 7, I don't use up even 1/3 of my taskbar. I have all this space I can use, and instead it's all squished to the left, making me take extra steps.  Are there any applications I can use to get this desired behavior, or else what route would you recommend to take to write this behavior myself? My first thought would be C# and the Windows taskbar APIs.  PS. If it's not clear what I'm asking for, please let me know, I'll try to be more specific.

There are three options for customizing taskbar buttons in Windows 7:   Always combine, hide labels Combine when taskbar is full Never combine   Is there any way to hide labels and not combine taskbar buttons? Or even better, to exclude only certain applications from combining?  My main problem is that I switch a lot between two instances of a single application, and having to hover over combined icon and then choosing the correct one. Alt-Tabbing is not a good alternative when I'm switching between more than three applications; clicking on taskbar only once is what I'm looking for.


What is the best way/software to create animated gif file like in mega.co.nz. This is sample files:     Thanks for any help or advice.

I'm sure you've seen Dribbblers upload animated mockups of their designs.   Here's an example:     I can create mockups on Photoshop and even apply simple Tween Animations to them but I can never get my GIFs to look like the example here.   What are Dribbblers using to create these animations?   Notice that the animations also include touch points and perfect motion. I would like to convert my Photoshop mockups to do the same.  How can I create an animated example of my mockups, similar to the ones created by Dribbblers?


We are currently under attack on one of our servers at a datacenter in Chicago.   1 gbps (peak) 600mbps average UDP flood port 80 (incoming) Consumed 20 TB bandwidth in 2.5 days   We have 50TB of bandwidth per month on this server and paying for the bandwidth is not an option (pricey).  Our host offers a protection plan for 1gbps attacks for $800/mo and $750 setup.  This is a lot of money but seems like the only option at this point to keep the website alive. The attack may only last a few more days.  Is there another host that has DDOS prevention built in or is there a more cost effective way of handling this? In a jam right now. Do we really have to pay for our servers plus $800 per month from now on just to prevent future bandwidth eating DDOS?  I am a small business that can barely afford this service (and still be profitable) but I can't imagine how scared I would be if this service could not be afforded.

This is a  about DoS and DDoS mitigation.   I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth.  Nobody can access my site because all the requests time out, and I can't even log into the server because SSH times out too!  This has happened a couple times before, and each time it's lasted a couple hours and gone away on its own.  Occasionally, my website has another distinct but related problem: my server's load average (which is usually around .25) rockets up to 20 or more and nobody can access my site just the same as the other case.  It also goes away after a few hours.  Restarting my server doesn't help; what can I do to make my site accessible again, and what is happening?  Relatedly, I found once that for a day or two, every time I started my service, it got a connection from a particular IP address and then crashed.  As soon as I started it up again, this happened again and it crashed again.  How is that similar, and what can I do about it?


I have 8/3 Romex wire and shop is 60 ft. From my house. Heard to many of different ways to do it, but I want it to be down safe and the right way. I need to know what size of subpanel and what breakers can I use? Wanting 3 outlets, 1 for lights and stereo, 1 for tools 15amp on tools nothing bigger than that and 1 for misc. Main panel in the house is 150amp cutler-hammer with 6 spaces still open.

I bought an old house that has a fuse box. The place has a milk barn that I want to convert to a workshop. Can I run 6/2 wire from the the two 120 volts wires coming from the fuse box?    I want to run it into a 200amp breaker box in the barn. I will be using a 220V dryer and maybe a welder if that is possible.